Joint for artificial body members



W mm E. SCR-IWAHZKQPF w fi JOINT FOR ARTIFICIAL BODY MEMBERS Filed Sept. 17, 1945 ELNVENTOW Em/7 Sammy/Mp1 Patented May 30, 1950 UNITED STATES PATENT OFFICE JOINT FOR ARTIFICIAL BODY MEMBERS Emil Schwarzkopf, Los Angeles, Calif.

Application September 17, 1945, Serial No. 616,681

1 Claim. 1

This invention relates to joints adapted to support artificial body members.

The joint is useful, for example, as a hip joint to support an artificial limb used in cases where the amputation is above the knee and near the pelvis. It can also be used at the knee joint for supporting an artificial leg in cases where the amputation is below the knee.

Joints for such purposes should be noiseless for obvious reasons. Accordingly, it has been proposed to use a lubricant between the moving parts of the joint. This, however, creates another diificulty; for, often, the lubricant escapes and soils the garments of the wearer.

It is an object of this invention to make it possible to enclose the bearing parts for preventing ingress of dust or other foreign matter, as well as to prevent escape of the lubricant.

It is another object of this invention to make possible the provision of a joint that is noiseless and requires no renewal of lubricant.

It is still another object of this invention to provide enclosures for the rolling bearing elements such that the joint may be disassembled and reassembled without the necessity of disturbing these elements. Accordingly, careless handling of the joint by repair men is not likely to result in the loss of any of the bearing parts.

It is still another object of this invention to provide a sturdy joint structure of this character that can be left without attention for long periods, and that has adequate bearing supporting surfaces in a relatively small space.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of several embodiments of the invention. For this purpose there are shown a few forms in the drawings accompanying and forming part of the present specification. These forms will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claim.

Referring to the drawings:

Figure 1 is an elevation of a joint incorporating the invention;

Fig. 2 is an elevation, partly in section, taken as indicated by the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary section on an enlarged scale, taken as indicated by the line 3-3 of Fig. l; and

Fig. 4 is an elevation of a modified form of the invention.

The joint structure illustrated in Figs. 1, 2, and 3 includes an upper arm I and a lower arm 2, and corresponds to the hip joint of the user. The outer surface of both of these arms are slightly convex, as indicated in Fig. 2, to provide a smooth exterior surface. The upper portion of arm I may be pivotally connected, as by the aid of a pin 3, to a belt member 4 that is adapted to be secured about the body of the wearer. The outer surface of the lower arm 2 is shOWh as flush with the exterior surface of the artificial limb 5. Arm 2 is fastened to limb 5 by a plurality of screws 6.

The lower end I of the arm I, as shown in Figs. 2 and 3, is bifurcated to provide sections 8 and 9 which straddle the upper end IU of the arm 2. These sections 8 and 9 have spaced parallel plane surfaces 8-a and 9-a between which the end It is accommodated, the opposite faces IBa and III-b of the end III being closely spaced to the surfaces 8--a and 9-a respectively.

The upper end II], as shown in Fig. 3, is provided with a circular through aperature II in which are mounted spaced rolling bearing structures I2 and I3, serving to connect the arms I and 2 for movement about an axis I I. The bearing structures I2 and I3 comprise, respectively, a plurality of rolling bearing elements I5 and I6, shown in this instance as hardened steel balls. The aperture I I is provided with an annular projection or flange II, the opposite sides of which provide thrust surfaces for the bearing elements I5 and I6, the surface of the aperture I I serving to support these elements radially. The aperture II thus provides the outer races I2a and I3-a of the bearing structures I2 and I3.

The inner races I2-b and I3--b for the bearing structures are provided, respectively, by washer-like members I9 and 20 carried on a pin structure 2| secured in the bifurcated lower end I of the upper arm I. The members I9 and 20 have, respectively, flanges I9-a and 26-0. adjacent their outer ends, which cooperate with the flange I! to confine the balls I5 and I6. In this way a combined radial and thrust bearing is provided for connecting the arms I and 2.

The bearing members I9 and 20 are secured to each other in an convenient way, as, for example, by pins 22 and 23 which are a forced fit in aligned apertures 24 and 25 in the members I9 and 29. In this way, the bearing structures I2 and I3 are maintained in assembled relation in the arm 2, even when separated from the arm I by the removal of the pin 2 I.

i in a threaded bore 2'l-a in the other section 21.

Sections 26 and 2''! each have conical heads 26'b and 21b respectively accommodated in countersunk openings provided on the opposite sides of the bifurcated end 7. When the sections26 and 21 are in assembled relation, they cooperate to form a cylindrical surface 2 la for mountingthe bearing members [9 and 20.

To facilitate assembly and disassembly of the pin 2 I, section 26 is provided with a non-circular opening 28 adapted to be engaged by a suitable wrench, While the section 21 is restrained from rotating by a pin 29-fixed in the arm 1 and en'- gaging a notch 80 formed inthe head 21--b.

The combined thickness of the bearing members l9 and is substantially the same as the space between the end portions 8 and 9 of the arm 1. Thus, when assembled in place on the pin 2|, the members [9 and 29 are frictional-1y restrained against movement about the axis l4. Since free angular movement about this axis is. required between the arms I and 2, the upper end ID of the lower arm 2 is of less thickness than this space to provide a, clearance of the order of a few thousandths of an inch between the opposite faces l0a and til-b of this end If) and the inner surfaces 8-a and 9a of the end 1.

The bearing structures l2 and I3 are sealed against ingress of dust or other foreign matter, as well as against the escape of lubricant by sealing rings or gaskets 3i and 32 of suitable resilient material, such as neoprene, interposed respectivel between the surfaces 8-a and l 0-a, and 9-a and i0b, and extending about the bearing structures. These rings 31 and 32 are secured to one of the end portions, such as the end portion I0 of the lower arm 2, as by being disposed in suitable grooves 3 l-a and 32a and secured in place.

When initially assembled, a small amount of suitable lubricant having a low freezing point is placed in the bearing structures I2 and 13. Due to the sealed construction which prevents escape of this lubricant, renewal or replacement thereof is not required.

The hinge structure can be readily adapted to correspond to the knee joint. Such an adaptation is illustrated in Fig. 4. In this instance, the upper arm 35 is securely attached to the bands 38, 31 that are adapted to encircle the leg above ened position.

the knee. Similarly, the lower arm 38 may be attached to the lower limb-encircling bands 39, 40. A limit, however, is placed upon the extent of angular movement between the arms. For this purpose, the lower arm 38 carries a stop pin 4! adapted to cooperate with ,a stop lug or abutment 42 carried by the bifurcated end of the upper arm 35. When these stop elements 4| and 42 are in contact, the knee joint is in a straight- In the process of sitting down, or the like, the upper arm 35 is permitted to turn in a clockwise direction, as indicated by the alternative position shown in dot-and-dash lines.

The inventor claims:

In a hinged device: a first arm having a bifurcated end providing substantially plane parallel inner, surfaces; a second arm having an apertured ear disposed between said surfaces, said ear having an annular and inwardly directed flange forming a pair of outer races; an inner race member disposed between and engaging the inner surfaces of said bifurcation and having inwardly facing annular shoulders at each side thereof providing inner races opposed to and on opposite sides of said outer races, said inner race member comprising two axially separable elements abutting each other; meansinterconnecting said axially separable elements to prevent their rotation with. respect to each other; a pair of sets of rolling elements disposed. between said inner and outer races and separated by said flange; means for retaining said axially separable elements inabutting relation to each other and said inner races and said rolling elements in said apertured ear; and means for clamping said bifurcation to said inner race member with the inner surfaces of the bifurcation engaging the outer surfaces of said innerrace member;

EMIL SCHWARZKOPF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date,

467,481 Hillebrand Jan. 19, 1892 620,999 Wambsgan Mar. 14, 1899 847,719 Arnold Mar. 19, 1907 1,008,048 Mueller Nov. 7., 1911 1,363,477 Lowe Dec. 28, 1920 1,365,654 Bott Jan. 18, 1921 2,042,882 Delaval-Crow June 2, 1936 2,134,288 McCann Oct. 25, 1938 FOREIGN PATENTS Number Country Date 404,600 France Dec. 6, 1909 

